The present invention relates generally to vehicles, and more particularly to a vehicle wheel bearing and to a method for controlling a vehicle.
Vehicles include automotive vehicles having wheel bearings wherein each wheel bearing includes a non-rotatable section and a rotatable section rotatably attached to the non-rotatable section. Typically a wheel is attached to the rotatable section, and the non-rotatable section typically is attached to a suspension system component. In some conventional vehicles, an anti-lock-braking-system (ABS) wheel speed sensor has a sensing component attached to the suspension system and has a sensed component in the form of a target ring attached to the rotatable section of the wheel bearing.
Vehicle control systems include, without limitation, vehicle stability enhancement systems. Conventional vehicle stability enhancement systems gather vehicle inputs (such as wheel speed and vehicle yaw rate) and adjust vehicle performance characteristics (such as suspension stiffness). In one known system, a magnetic sensor has a sensing component attached to an end of an arm whose other end is attached to a suspension system component and has a sensed component in the from of magnetic material molded into the sidewall of a tire. The sensor output is used for determining a longitudinal component of the force applied to the tire, wherein the determined longitudinal force component is an input to a vehicle anti-lock brake system. In another known system, a stress-based load sensor is attached to the wheel bearing outside the sealed bearing cavity and has an output used for a vehicle control system.
Conventional stress-based load cells have been used in vehicle development for determining the three-axis components of a force applied to the wheel bearing through tire loads. The determined force was used to improve vehicle design. In one conventional test application, the load cell had one load-cell component attached to the non-rotatable section of the wheel bearing and had another load-cell component attached to a suspension-system component. In another conventional test application, the load cell components were installed in an external load cell module which was attached to the rotatable section of the wheel bearing outside the sealed bearing cavity.
What is needed is an improved vehicle wheel bearing and an improved method for controlling a vehicle.
An expression of an embodiment of the invention is for a vehicle wheel bearing including a vehicle-wheel-bearing non-rotatable section, a vehicle-wheel-bearing rotatable section, and at least one sensor. The vehicle-wheel-bearing rotatable section is rotatably attached to the non-rotatable section. The at-least-one sensor is attached to at least one of the non-rotatable and rotatable sections and has an output used for determining at least one component of a force applied to the rotatable section. The at-least-one sensor measures temperature.
An expression of another embodiment of the invention is for a vehicle wheel bearing including a vehicle-wheel-bearing non-rotatable section, a vehicle-wheel-bearing rotatable section, and at least one sensor. The vehicle-wheel-bearing rotatable section is rotatably attached to the non-rotatable section. The at-least-one sensor is attached to at least one of the non-rotatable and rotatable sections and has an output used for determining at least one component of a force applied to the rotatable section. The at-least-one sensor measures the distance between the non-rotatable and rotatable sections.
An expression of an additional embodiment of the invention is for a vehicle wheel bearing including a vehicle-wheel-bearing non-rotatable section, a vehicle-wheel-bearing rotatable section, and at least one sensor. The vehicle-wheel-bearing rotatable section is rotatably attached to the non-rotatable section. The at-least-one sensor is attached to at least one of the non-rotatable and rotatable sections and has an output used for determining at least one component of a force applied to the rotatable section. The rotatable section includes a first race, the non-rotatable section includes a second race, and the first and second races define a raceway. The vehicle wheel bearing also includes rolling elements positioned in the raceway. The at-least-one sensor senses the passage of the rolling elements around the raceway past the at-least-one sensor.
An expression of a further embodiment of the invention is for a vehicle wheel bearing including a vehicle-wheel-bearing non-rotatable section, a vehicle-wheel-bearing rotatable section, and at least one sensor. The vehicle-wheel-bearing rotatable section is rotatably attached to the non-rotatable section. At least one of the non-rotatable and rotatable sections includes at least a portion of an inboard bearing seal, at least one of the non-rotatable and rotatable sections includes at least a portion of an outboard bearing seal, and the outboard bearing seal is spaced apart from the inboard bearing seal. The at-least-one sensor is positioned between the inboard and outboard bearing seals and has an output used for determining at least one component of a force applied to the rotatable section.
A method of the invention is for controlling a vehicle having a wheel bearing including a non-rotatable section, including a rotatable section rotatably attached to the non-rotatable section, and including rolling elements positioned between the non-rotatable and rotatable sections. The method includes steps a) through c). Step a) includes attaching at least one sensor to at least one of the non-rotatable and rotatable sections, wherein the at-least-one sensor has an output and measures at least one of the passage of the rolling elements, the distance between the non-rotatable and rotatable sections, and a temperature. Step b) includes determining at least one component of a force applied to the rotatable section from the output of the attached at-least-one sensor of step a). Step c) includes controlling the vehicle based at least in part on the determined at-least-one component of step b).
Several benefits and advantages are derived from one or more of the expressions of the embodiments and/or from the method of the invention. Attaching a temperature, a distance, and/or a rolling-element-passage-sensing sensor (whose output is used for determining at least one component of a force applied to the rotatable section of the wheel bearing) to at least one of the non-rotatable and rotatable sections of the wheel bearing yields an accurate force determination at the wheel bearing, as can be appreciated by those skilled in the art. Positioning any type of sensor (whose output is used for determining at least one component of a force applied to the rotatable section of the wheel bearing) between the inboard and outboard seals protects the sensor from road and environmental hazards. Such sensors are useful, for example, in controlling a vehicle.